–noun
1. a vehicle with two wheels in tandem, usually
propelled by pedals connected to the rear wheel by a chain, and having
handlebars for steering and a saddlelike seat.
–verb (used without object)
2. to ride a bicycle.
–verb (used with object)
3. to ship or transport directly by bicycle or other means.

The bicycle, bike, or cycle, is a pedal-driven, human-powered vehicle with two wheels attached to a frame, one behind the other.

First introduced in
19th-century Europe, bicycles now number approximately one billion
worldwide, providing the principal means of transportation in many
regions. They also provide a popular form of recreation,
and have been adapted for use in many other fields of human activity,
including children's toys, adult fitness, military and police
applications, courier services, and cycle sports.

The basic shape and
configuration of a typical bicycle has hardly changed since the first
chain-driven model was developed around 1885, although many important
details have been improved, especially since the advent of modern
materials and computer-aided design. These have allowed for a
proliferation of specialized designs for particular types of cycling.

The bicycle has had a
considerable effect on human society, in both the cultural and
industrial realms. In its early years, bicycle construction drew on
pre-existing technologies; more recently, bicycle technology has, in
turn, contributed ideas in both old and new areas.

Every cyclist has an ideal cadence(pedaling speed), and an ideal amount of resistance from the pedals.
When you are pedaling at your ideal cadence, you are putting out the
greatest amount of power that you are able to sustain efficiently. You
select your cadence by shifting gears. The gear needed to allow your
"ideal" cadence will depend on the slope of the road, the wind
conditions, and your own condition at any given time.

Alan Turing was known for
riding his bicycle with a gas mask on. He claimed it relieved
his allergies.

Twilight ZoneEpisode _You Drive_ (avi)(113.7megs) - Season 5, Episode 14 - "The victim, a kid on a bicycle,
lying injured, near death. But Mr. Pope hasn't time for the victim, his
only concern is for himself. Oliver Pope, hit-and-run driver, just arrived
at a crossroad in his life, and he's chosen the wrong turn. The hit occurred
in the world he knows, but the run will lead him straight into - the Twilight
Zone."

my bike: GT Talera 1997 - "Valkyrie"

"As a kid, I had a dream - I wanted to own my own bicycle," said Beatle
John Lennon, in Bicycling magazine. "When I got the bicycle, I
must have been the happiest boy in Liverpool, maybe in the world.
I lived for that bike. Most kids left their bikes in the backyard
at night. Not me. I insisted on taking mine indoors and the
first night I even kept it in my bed."

Female Emancipation

The bicycle was recognised by nineteenth-century feminists
and suffragists as a "freedom machine" for women. American Susan B.
Anthony said in a New York World interview on February 2, 1896: "Let me
tell you what I think of bicycling. I think it has done more to
emancipate women than anything else in the world. It gives women a
feeling of freedom and self-reliance. I stand and rejoice every time I
see a woman ride by on a wheel...the picture of free, untrammelled
womanhood."

In the 1890s the bicycle craze
led to a movement for so-called rational dress, which helped liberate
women from corsets and ankle-length skirts and other restrictive
garments, substituting the then-shocking bloomers.

Social Implications

In cities, bicycles helped reduce crowding in inner-city tenements by
allowing workers to commute from more spacious dwellings in the
suburbs. They also reduced dependence on horses, with all the knock-on
effects this brought to society. Bicycles allowed people to travel for
leisure into the country, since bicycles were three times as energy
efficient as walking, and three to four times as fast. Cycling has many
health benefits and does not directly contribute to global warming or
environmental pollution.

While pedaling at night, Albert Einstein observed that the bobbling beam cast
from his headlamp always traveled at the same speed, whether he was
cruising at a quick clip or coasting to a stop. The theory - that
light from a moving source has the same velocity as light from a
stationary source - as born on that ride. "I thought of it while
riding my bicycle," remains one of Einstein's most renowned quotes.

Another
favorite saying - "Life is like riding a bicycle. To keep your
balance, you must keep moving" - is indicative of the joyful,
compassionate scientist's love of the bicycle. Early in his schooling
at Munich University in Germany, he would take bicycle tours with
fellow scientists to contemplate the world at large. And during his
final years, while at Princeton University during the early 1950s,
when the automobile was the mode of transportation du jour, Einstein
chose his trusty steed over any other modern engineering marvels.
Indeed, the most lasting image of the wild-haired genius is that of him tooling around, atop his bicycle, with his infectious grin, gleefully imagining the next revolutionary idea.

psychedelic rock track _Bike_ MP3 by Pink Floyd off of _Piper At The Gates Of Dawn_ 12" (1967)

Pink Floyd - _Dark Side Of The Moon_/Wizard Of Oz_ - synchronicity - Mrs. Gulch AKA Wicked Witch of the West appears riding
her bike at the same moment you hear the alarm clock bells going off at
the beginning of the track _Time_ MP3 (192k); The chimes in _Time_ start and stop when the evil
lady on the bike rides up, and the chimes ring as the clocks and such are
going off at the end.

folk punk track _The Argument_ MP3 by This Bike Is A Pipe Bomb off of _Front Seat Solidarity_ 12" on Plan It X (2001)

On March 02, 2006 at
5:30 am an Ohio University police officer spotted a bicycle attached to
the Oasis restaurant bearing a promotional sticker for the band. The
officer saw the words, "This Bike Is a Pipe Bomb" and became
"concerned". The area was cordoned off, and part of the campus was
closed for several hours. The bicycle was subsequently destroyed by the
Columbus bomb squad despite assurances from the bike's owner that it
was just a sticker. The owner, a graduate student, was initially
charged with "inducing panic", a misdemeanor. However, the charges were
dropped a few days later.